package com.yonyou.brigade.third_parties.didi.util;

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.security.Key;

/**
 * @author kangfw5
 * @date 2019-06-20
 */
public class DESUtil {
    //算法名称
    public static final String KEY_ALGORITHM = "DES";
    /**
     * 算法名称/加密模式/填充方式
     * DES共有四种工作模式-->>ECB：电子密码本模式、CBC：加密分组链接模式、CFB：加密反馈模式、OFB：输出反馈模式
     */
    public static final String CIPHER_ALGORITHM = "DES/CBC/PKCS5Padding";

    /**
     * 生成密钥key对象
     *
     * @param keyStr 密钥字符串
     * @return 密钥对象
     * @throws Exception
     */
    private static SecretKey keyGenerator(String keyStr) throws Exception {
        DESKeySpec desKey = new DESKeySpec(keyStr.getBytes("UTF-8"));
        //创建一个密匙工厂，然后用它把DESKeySpec转换成
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey securekey = keyFactory.generateSecret(desKey);
        return securekey;
    }

    /**
     * 加密数据
     *
     * @param data 待加密数据
     * @param key  密钥
     * @return 加密后的数据
     */
    public static String encrypt(String data, String key) throws Exception {
        Key deskey = keyGenerator(key);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        // 实例化Cipher对象，它用于完成实际的加密操作
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        // 初始化Cipher对象，设置为加密模式
        cipher.init(Cipher.ENCRYPT_MODE, deskey, iv);
        byte[] results = cipher.doFinal(data.getBytes("UTF-8"));
        // 执行加密操作。加密后的结果通常都会用Base64编码进行传输
        return Base64.encodeBase64String(results);
    }

    /**
     * 解密数据
     *
     * @param data 待解密数据
     * @param key  密钥
     * @return 解密后的数据
     */
    public static String decrypt(String data, String key) throws Exception {
        Key deskey = keyGenerator(key);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        //初始化Cipher对象，设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, deskey, iv);
        // 执行解密操作
        return new String(cipher.doFinal(Base64.decodeBase64(data)));
    }

    public static void main(String[] args) throws Exception {
        String source = "amigoxie";
        System.out.println("原文: " + source);
        String key = "A1B2C3D4";
        String encryptData = encrypt(source, key);
        System.out.println("加密后: " + encryptData);
        String decryptData = decrypt(encryptData, key);
        System.out.println("解密后: " + decryptData);
    }
}
